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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The risk for depression increases at two opposite times of the year--late spring/early summer and late fall/early winter. In 15% of patients with recurrent major depression, depressive episodes regularly recur on an annual basis in one of the two seasonal risk periods. Thus, there are primarily two forms of seasonal affective disorder: recurrent fall-winter depression and recurrent spring-summer depression. The opposite seasonal types of depression tend to have opposite vegetative symptoms. Sleep, appetite and weight increase in winter depression and decrease in summer depression. An important implication of the seasonality of depression is that some type of depression may be caused by changes in the physical environment and that manipulations of the physical environment may be used as treatments. There is now extensive evidence that exposure to bright artificial light is an effective treatment of recurrent winter depression. A corollary is that seasonal deficiency of natural light probably induces winter depression. There have been considerable efforts to elucidate the biological mechanisms of winter depression and its response to phototherapy. Although no single system has been shown to be responsible for the syndrome, there is evidence that the indole hormone melatonin, the indole neurotransmitter serotonin, and the peptide neurohormone corticotropin releasing hormone (CRH) play roles in the pathophysiology and phototherapy of winter depression.
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PMID:Seasonal vulnerability to depression. Implications for etiology and treatment. 130 42

CRH, a hypothalamic peptide that is the most potent ACTH secretagogue known, also appears to be produced in the cerebral cortex and spinal cord. Depressed patients have blunted responses to exogenous CRH and normal to high concentrations of CRH immunoreactivity in single morning samples of lumbar cerebrospinal fluid (CSF). Although these data suggest that depression may be associated with hypersecretion of CRH, it has also been postulated that central nervous system insufficiency of CRH might have a pathophysiological role in certain depressive syndromes. We continuously sampled lumbar CSF via indwelling subarachnoid catheters from 1100-1700 h and measured CRH at 10-min intervals in depressed patients and normal subjects. A standardized mixed liquid meal was administered at 1300 h. CSF CRH was strikingly reduced in depressed patients compared to normal subjects [4.2 +/- 1.1 pmol/L vs. 13 +/- 2.1 pmol/L (mean +/- SEM), respectively, P less than 0.01 by Wilcoxon test]. CSF CRH concentrations rose progressively during the experiment in both groups, suggesting a diurnal rhythm and, possibly, response to a test meal. CRH had a very brief half-life in CSF (less than 10 min), suggesting that the spinal cord is the origin of CRH in lumbar CSF. The rapid transients in CSF CRH concentration demonstrate that single samples provide very limited information. There were no intraindividual correlations between CSF CRH concentrations and those of either plasma ACTH or cortisol, both of which rose in response to eating. The present data show that impaired central nervous system secretion of CRH can exist during states of severe depression.
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PMID:Serial cerebrospinal fluid corticotropin-releasing hormone concentrations in healthy and depressed humans. 131 85

This study examined hypothalamic-pituitary-adrenal axis functioning in a group (n = 25) of very carefully screened normal children with considerable attention to issues of adaptation and procedural stress. The subjects (mean age 10.3 +/- 1.6 y) were selected as "supernormal" controls as a part of a large psychobiologic study of childhood depression. After careful acclimatization over 24 h, the subjects underwent all-night sampling of plasma cortisol every 20 min, then the following evening had a corticotropin releasing hormone (CRH) stimulation test (using human CRH). Human CRH resulted in a rapid stimulation of adrenocorticotropin and cortisol. Adrenocorticotropin levels increased from 6.8 +/- 3.5 (+/- SD) pmol/L (30.7 +/- 16.1 pg/dL) to a peak of 11.6 +/- 5.5 pmol/L (52.9 +/- 24.8 pg/mL) at 15 min with return to baseline levels by 60 min. Cortisol levels increased from 131.4 +/- 59.7 nmol/L (4.8 +/- 2.2 micrograms/dL) to a peak of 427.0 +/- 113.5 nmol/L (15.5 +/- 4.1 micrograms/dL) at 30 min with return to baseline by 120 min. The cortisol peak was significantly greater (p less than 0.05) in boys [474.6 +/- 129.7 nmol/L (17.2 +/- 4.7 micrograms/dL)] than in girls [366.9 +/- 52.4 nmol/L (13.3 +/- 1.9 micrograms/dL, p less than 0.05)]. Age, body mass index, and pubertal status were not significantly related to hypothalmic-pituitary-adrenal axis measures. Nocturnal cortisol reached a nadir at 160 +/- 60 min after sleep onset (0102 h) and a peak 480 +/- 60 min after sleep onset (0612 h). Nocturnal cortisol levels were significantly (positively) correlated with human CRH-stimulated cortisol (r = 0.56, p = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Corticotropin releasing hormone stimulation test and nocturnal cortisol levels in normal children. 132 74

It has been suggested that the well-documented hypercortisolaemia found in a proportion of patients with severe depression occurs either in response to excessive secretion of corticotrophin-releasing hormone-41 (CRH-41) from the hypothalamus, or as a consequence of up-regulation of pituitary CRH-41 receptors. The attenuation of the normal ACTH response to CRH-41 in these subjects is thought to result from inhibition of corticotrophin secretion by elevated cortisol levels. We tested these hypotheses by examining ACTH responses to metyrapone, an 11 beta-hydroxylase inhibitor which blocks the formation of cortisol, followed by CRH-41 in 15 severely depressed in-patients diagnosed according to DSM-IIIR criteria. Patients were assigned to two groups according to their response to overnight administration of 1 mg dexamethasone: suppressors (8) and nonsuppressors (7). A third group consisted of 6 healthy matched controls. Metyrapone 750 mg was given 4-hourly for 24 h and samples were taken for cortisol and ACTH. Six of the original 15 patients (3 from each group) were given a bolus dose of 100 micrograms human CRH-41 intravenously after 24 h of metyrapone, and ACTH levels were measured over 2 h. Falls in circulating cortisol in response to metyrapone were similar in all three groups. However, we found exaggerated rises in ACTH amongst the nonsuppressors, as compared to the suppressors and the control group, after metyrapone.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of metyrapone on the pituitary-adrenal axis in depression: relation to dexamethasone suppressor status. 133 55

This study defines the pituitary B-endorphin (BE) secretory response to a low dosage (0.3 ug/kg) of human corticotropin releasing hormone (CRH) in depressed patients and normal controls pretreated with metyrapone. We find no difference in the B-endorphin response to CRH in depressed subjects without evidence of HPA overactivity, compared with controls. This finding is contrasted with other data demonstrating a blunted B-endorphin response to CRH in depressives. The influence of metyrapone pretreatment on the pituitary B-endorphin response to CRH through a mechanism that minimizes the impact of cortisol negative feedback is discussed. Future studies which include low dose CRH infusion both in the presence and in the absence of metyrapone pretreatment will help investigate alterations in the regulation of pituitary B-endorphin secretion in depression including the possibility of increased pituitary sensitivity to the negative fast feedback of cortisol.
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PMID:B-endorphin response to a low dosage of human corticotropin releasing hormone during metyrapone administration in depression. 147 19

In this study, we have measured the following biological variables in 78 depressed inpatients: adrenocorticotrophic hormone (ACTH) responses to corticotropin releasing factor (CRH: 100 micrograms intravenously), postdexamethasone cortisol and ACTH values, and circulating concentrations of L-tryptophan (L-TRP). Patients were categorized according to the DMS-III as (1) minor depression, (2) simple major depression, and (3) major depression with melancholia/psychotic features. By means of various pattern recognition methods, we determined whether these diagnostic groups constitute discrete biological classes or form relevant stages (i.e., continuous categories) in a continuum of progressing biological dysfunction. We established that unipolar depression constitutes one biological continuum characterized by a progression of lower CRH-induced ACTH responses, lower L-TRP levels, and higher postdexamethasone cortisol and ACTH values along the diagnostic spectrum. However, the biological differences in these markers between melancholia and minor depression are quantitatively prominent to the extent that they become qualitative. These findings support the biological heterogeneity hypothesis of melancholia. Simple major depression is a heterogeneous class with regard to the biological markers employed.
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PMID:Biological heterogeneity of melancholia: results of pattern recognition methods. 165 16

Human corticotropin releasing hormone (h-CRH) was administered to 14 patients with major depression, after premedication with an overnight dose of 1.5 mg dexamethasone. Cortisol response, expressed as area under the time course curve (AUC), was significantly higher in the 14 patients than in a group of 13 age-matched control subjects (9.4 +/- 7.6 ng x min x 1,000/ml vs. 3.1 +/- 3.6 ng x min x 1,000/ml). Corresponding AUC values for plasma adrenocorticotropic hormone (ACTH) were also significantly higher in patients than in control subjects (4.9 +/- 1.4 pg x min x 1,000/ml vs. 2.6 +/- 0.9 pg x min x 1,000/ml). After patients were treated with trimipramine (200 mg/day) for 6 weeks, the combined dexamethasone/h-CRH test was repeated. At that time, depression scores were significantly improved and the patients' cortisol response pattern became indistinguishable from that of controls. While plasma cortisol output normalized during treatment with trimipramine, ACTH release remained exaggerated. The combined dexamethasone/h-CRH challenge test may be of particular value in the detection of state-dependent changes of pituitary-adrenocortical neuroregulation.
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PMID:Repeated administration of the combined dexamethasone-human corticotropin releasing hormone stimulation test during treatment of depression. 166 30

1. Rhesus monkeys were equipped with a novel intracerebroventricular (i.c.v.) cannula system and trained to respond under operant schedules of food presentation or termination of stimuli associated with the delivery of shock (escape). 2. CRH decreased food-maintained behavior in a dose-related manner over the range of (0.3-10 micrograms/kg) but did not affect escape responding, demonstrating a selective effect on food-maintained responding. 3. This selective effect was related to the tendency for responding to stop after delivery of a food pellet when higher doses of CRH were given, consistent with the notion that a conditioned aversion to food was established in the presence of CRH. 4. This may suggest that in hyperaroused clinical states such as depression and anorexia nervosa, focus is shifted away from appetitive tasks as a result of increased levels of CRH.
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PMID:Selective anorexigenic effects of corticotropin releasing hormone in the rhesus monkey. 186 19

CRH seems to be of fundamental importance in depressive illness. Melancholic depressed patients, with a syndrome of hyperarousal, have increased activity of CRH-producing neurones. Conversely, there is evidence to support the notion that patients with atypical depression, a syndrome of hypoarousal, have decreased activity of CRH-producing neurones. CRH-induced kindling is a possible model for the natural history of depressive illness. Finally, effective treatments for depressive illness, such as tricyclic antidepressants, decrease CRH production, and drugs, such as carbamazepine, effective in preventing the recurrence of affective disorder, also decrease CRH production. Interestingly, these drugs are not particularly effective in the treatment of atypical depression, which seems to be related not to an activation of CRH-producing neurones, but rather to a decrease of CRH secretion.
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PMID:Role of corticotrophin releasing hormone 41 in depressive illness. 203 28

The behavioral consequences of the central administration of corticotropin releasing hormone (CRH) in rhesus monkeys was determined using food-maintained behavior. Acute doses of CRH (0.003 ng/kg-10 micrograms/kg, i.c.v.), decreased responding for food in a dose- and time-related manner. With intermediate doses, responding occurred at a high rate until food was delivered, and then abruptly ceased for several minutes. Previous studies have attributed similar effects to the noxious properties of certain drugs. Acute doses had no effect on home cage food consumption, body weight, or responding for food on subsequent days. When CRH was given repeatedly for several days, its behavioral suppressant effects increased. Home cage food intake, body weight, and subsequent responding for food decreased for up to 6 weeks before returning to normal. These results suggest that sustained elevations in central levels of CRH can result in a sensitization to its anorexigenic effects, an effect that has not been reported in other species. Because hyperaroused clinical states such as depression and anorexia nervosa are characterized biochemically by hypercortisolism and elevated CRH in CSF, these anorexigenic effects may corroborate a potential role for CRH in affective disorders.
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PMID:Corticotropin releasing hormone produces profound anorexigenic effects in the rhesus monkey. 204 89


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